1. Field of the Invention
The present invention relates generally to a vehicle top with a roof structure of movable panels, and more particularly to a roof structure with extensible roof panels to serve as a sun shade and snow shield over the windshield and rear window of an automobile.
2. Description of the Prior Art
There is a commonly encountered problem when parking a car in the outdoors under the hot summer sun; the temperature within the car goes up very quickly; seats, dashboard and steering wheel quickly become scorching, and people who enter the car instantly break out into perspiration, which is not a pleasant experience to the driver and passengers.
On the other hand, to leave a car parked in the outdoors in snowy winter presents another sort of problem, i.e. the falling snow or sleet piles up and covers the windshield and rear window. The driver has to scram and clear the windshield and rear window before driving.
These problems and the needs to alleviate them have been recognized long ago. Many different proposals have been explored over the years to address these concerns, however none of them was very effective or widely adopted. The common drawback of such proposals was that they only partially solved the problem, while creating other problems or negative side effects which made them impractical.
For example, U.S. Pat. No. 4,229,035 to Newman discloses a vehicle windshield rain deflector system which employs a hydraulic pump to actuate a pair of hydraulic cylinders to move a rain deflector in front of the windshield. It can only cover a small portion of the windshield area against head on falling rain, little use if the wind blows from a side direction, furthermore the always present rain deflector in front of the windshield becomes an annoying hindrance to the vision of the driver. Most drivers would rather have a clear and unobstructed front view during driving. The always present shadow from the rain deflector on the windshield becomes another annoying drawback when the driver or front seat passenger wants to enjoy the sunshine in the morning or afternoon when the sunshine is not very hot.
Similarly, U.S. Pat. No. 3,379,467 to Brush discloses a windshield visor which features a permanent visor panel to cover the whole windshield area. The driver's view is significantly confined. While it can prevent glare from the high noon sun, it also prevents the driver from enjoying sunshine when it is not very strong in the morning or afternoon.
U.S. Pat. No. 3,297,356 to Francis discloses an automobile windshield rain visor featuring a removable tubular member attached to the car top by means of vacuum cups or magnets. It must be installed or removed manually every time it is used, and it is quite bulky and inconvenient, either to use or to store. None of the aforesaid proposals has been widely accepted in the market place.
In order to solve the foregoing problems, there are a number of products being marketed, through none of them is very effective. It also happens tht those products which can reduce the sun heat transmitting into car cannot prevent snow from falling onto it.
For example, some devices provides a sun shade internally mounted on the car window, of either curtain or shutter types; some others provide externally mounted sun visor which is, in general a narrow strip or plate, fixed transversely on the front edge of the car roof and extended over the windshield and can only cover a small portion of the windshield area. As it is fixed and extended in the forward direction, it will increase the aerodynamic drag force aero when the car is moving forward; thus, fuel consumption will be increased. Still, others provide a fixed shutter-type louvered shade panel mounted externally on the rear window which has no effect on the windshield, but has the drawback of partially blocking the rearview of the driver. With regard to the canvas car cover, it is so clumsy to unpack and spread over the car, and so easy to collect dust and dirt, it is not widely used.
As to the movable car roof, there are many different types available relating to the sun roof feature. Howwever a sun roof feature is for the purpose of receiving sunshine into the car, not for providing a sun shade or a snow shield to the windshield and rear window. Furthermore, a sun roof feature mostly confines the motion of the roof panel between the windshield and the rear window, not extending over the windshield and rear window areas.
This invention provides an extensible car roof, with slidable front and rear panels sandwiched in a car roof enclosure and driven by a D.C. motor. By pressing a two-way switch, the D.C. motor will move the front and rear panels out of the roof enclosure to hang over the windshield and rear window respectively to serve as a sun shade or a snow shield. Upon throwing the two-way switch in the other direction, the D.C. motor will rotate in a reversed direction; thus, the front and rear panels will be retracted into the roof enclosure for storage and to reduce the drag force when car is moving forward. Thereby, this invention provides a ready and handy sun shade and snow shield for a car so as to give the driver and passengers a more comfortable and convenient drive and ride in the hot summer and in the snowy winter.